The Evidence For Evolution Artificial Selection Artificial Selection

The Evidence For Evolution

Artificial Selection

Artificial Selection Wild-type vs. Domesticated Corn

Artificial Selection

Artificial Selection Russian geneticist Dmitry K. Belyaev

Artificial Selection

Piebald coat color in dometsicated animals and foxes

After 8 – 10 generations: • Changes in coat color • Floppy ears • Rolled tails After 15 – 20 generations: • Foxes with shorter tails and legs • Underbites / overbites • Barking!

How is artificial selection evidence for evolution?

The Fossil Record Absolute (Radiometric) Dating = based on principle that isotopes decay to daughter isotopes at a constant rate Half-Life = time required for 50% of parent isotope to decay

The Fossil Record Absolute (Radiometric) Dating = based on principle that isotopes decay to daughter isotopes at a constant rate Parent Isotope Daughter Isotope Half-Life Effective Dating Materials that can be Dated Uranium-238 Lead-206 4. 5 billion 10 million – 4. 6 billion Volcanic Rock Potassium-40 Argon-40 1. 3 billion 50, 000 – 4. 6 billion Volcanic Rock Rubidium-87 Strontium-87 47 billion 10 million 4. 6 billion Metamorphic or Igneous Rock Carbon-14 Nitrogen-14 5730 100 – 70, 000 Wood, charcoal, peat, bone, shell Half-Life = time required for 50% of parent isotope to decay

Try It! Your measurements indicate that a fossilized skull you unearthed only contains about 1/16 th the carbon -14 of the skulls of present-day animals. What is the approximate age of the fossilized skull?

Relative Dating

Relative Dating KT Iridium Layer – Newfoundland KT Iridium Layer – Italy

Try It!

Extinct Organisms

Transitional Forms

How is the fossil record evidence for evolution?

Morphological Homology – Anatomical Mammalian forelimbs

How are homologous structures evidence for evolution?

Vestigial Structures Vestigial Bones in Snake and Human

Vestigial Structures Python with vestigial appendage

How are vestigial structures evidence for evolution?

“How far more interesting does out study become when we regard every production of nature as one which has a history” – Darwin, 1859 Blind Salamander Flightless Kiwi

• Why? Seems Odd? QWERTY Key Arrangement

• At least as good, possibly better. • Why don’t we use it? DVORAK Key Arrangement

“Evolution is like modifying a machine while it’s running” – Karl Liem

Don’t Be Fooled By Analogous Structures! What do they tell us about?

Homology or Analogy? Porcupine’s Quills and Cactus’s Spines Cat’s Paw and Human Hand Owl’s Wing and Hornet’s Wing

Developmental Homologies Match and Order the Embryos!

Developmental Homologies Stage 1 2 3 # Correct “ ” # Incorrect “x”

“Ontology Recapitulates Phylogeny”

Molecular Homology 7% 3. 1% 1. 6% 1. 2%

Molecular Homology

In all living things…

Biogeography

WE CAN SEE IT HAPPEN!

Piecing Together the Evolution of Whales What are the different types of evidence that were used?

“Internal Consistency”